Finding the Third Proportional to 300.75 and 646.69

Step by Step Solution

1. Step 1: Write the proportion equation
   300.75 : 646.69 = 646.69 : x
2. Step 2: Convert to fraction form
   300.75/646.69 = 646.69/x
3. Step 3: Cross multiply
   300.75x = 646.69 × 646.69
4. Step 4: Simplify right side
   300.75x = 418,204.72
5. Step 5: Solve for x
   x = 418,204.72/300.75
6. Step 6: Final answer
   x = 1,390.54